Coolant vs. Water : Which Is Safest for Your Vehicles?

An overheating engine is one problem that you should not ignore. The radiator is the component on your vehicle that helps keep the engine cool. Your vehicle’s engine gets rapidly destroyed without a proper cooling system due to the heat produced after internal combustion. Typically, an engine coolant maintenance is crucial to your engine’s life.

If you love your vehicle or machine, then you must know how important it is to take good care of it. Regular maintenance is vital to ensure the engine lasts. When asked, a lot of people cannot tell the difference between using a coolant vs. water. Most people, however, opt to use water rather than the coolant, but is it the best option? Read on this guide to find out which one works better for your car radiator. While both water and coolant work to cool your vehicle’s engine, the efficiency is not similar.


A coolant is a product manufactured chemically and is premixed with water. A coolant vs. antifreeze is not the same thing. Antifreeze is usually added into a coolant to prevent it from freezing during winter or cold seasons. Antifreeze works by altering the temperature at which the coolant either boils or freezes. However, people may, at times, refer to coolant as radiator fluid. Propylene or ethylene is often used as an antifreeze agent.radiator coolant

A cooling system is primarily considered to be the heart of your vehicle. It usually pumps the coolant via the radiator, engine block, and cooling system to ensure the system operates at optimum temperatures. Whether you call it antifreeze or coolant, the fluid is usually a 50-50 mixture of propylene or ethylene and water.

If mixed well, a coolant can protect up to a temperature of 265º C and a freeze-protection of up to -34º C. The fluid also has chemical inhibitors that help protect the cast iron, copper, aluminum, or any other metals in the cooling system from rust or corrosion.

An engine coolant also has additional additives that lubricate water pumps and seals. Your fluid’s color may be red, green orange depending on the brand or type. You ought to always ensure that you use the recommended brand in your vehicle’s manual because every vehicle’s cooling system is developed and tested using the indicated coolant.

Now that you know the essence of having a coolant every time in your vehicle, it is crucial to check coolant levels if it has been a while before you did so. Checking a coolant is very easy, as it is usually a clear tank that you can check without removing the cap. Typically, the recommended levels are indicated on the tank.

Moreover, you should check the manual for the recommended interval between the service of the coolant system. Most recommend flushing and changing the coolant after about 40,000 to 50,000 miles. If you cannot do it yourself, ask the experts to do it for you at a reputable store. Most engine coolants are usually toxic; hence you should be careful.

Moreover, it is quite natural for residue and dirt to clog the car’s cooling system. Therefore, a good idea would be to do a full radiator flush once in a while. Also, keep in mind that an ideal coolant usually has low viscosity, high thermal capacity, and is low cost.


Water is also known to keep your engine cool. Using water to top up the coolant commonly occurs as most people fail to understand how a radiator typically functions. Water does not have the qualities of a suitable coolant due to the low thermal capacity and high viscosity. Pure water boils at 100 degrees, but with impurities such as calcium, magnesium, or chlorine, the boiling point lowers up to about 85 degrees. These minerals deposit and clog the cooling system after a long time of using water as a coolant.Distilled water

When you use water in a radiator, the engine and radiator may start building some mineral deposits, which causes damage. There are also other additives in ta coolant that prevent rust while water accelerates it. As the water boils, it starts to expand and also releases the gases dissolved in it. Your vehicle’s cooling system is usually a closed system, and hence this expansion causes the buildup of pressure. At some point, either the radiator, hose, or water pump has to give way!

Adding too little water would mean that the coolant is too small to circulate efficiently, while too much water means the coolant would not work optimally. Many a time, your vehicle’s engine is damaged when the cooling system is neglected. Using only water may also, in the long run, cause engine failure.

Therefore, even if it is a case of coolant vs. distilled water, a coolant will always be the better option. However, water may be used in case of emergencies or where there is no place you can buy a coolant nearby. Water is generally easy to find and, in some cases, free; hence it tends to be a more popular option.

If you have been using water for too long and are worried that some parts of the cooling system may have rusted, you must use flush the cooling system by using quality radiator flash. Always remember that cheap is expensive. You may think that you are saving up money by using water, which is a more affordable coolant, but this may eventually lead you to more trouble. At times, the damage caused may be irreparable.

Generally, water can never be as efficient as a radiator coolant. Nonetheless, the coolant fluid also needs to be mixed with water; thus, water is not that bad either. The mixture is, however, done at the right ratio to ensure the coolant works optimally.

Coolant vs. Water (FAQs)

Q: Can water be used instead of coolant?

Yes, water may be added to cool your engine. However, it is often not recommended because pure water boils faster than a coolant does hence making your engine overheat. Your vehicle’s radiator cannot work if there is not enough coolant in the engine. However, if you are wondering, “can I use water instead of coolant in an emergency,” then the answer is a yes. It would help you out of a situation whereby accessing water would be easier than finding a coolant. Therefore, if it is a do or dies situation, do not hesitate to use water.

Q: Which is better coolant or water?

There is a significant difference between coolant vs. water. When you compare a coolant vs. water heat transfer, water does a great job at removing heat more efficiently, but it has a low boiling point. However, a coolant is better because it is a mixture of ethylene and water, which protects against corrosion and offers a higher boiling point. Water helps keep your engine cool, although it does not match the efficiency of a coolant. With time, water in the system evaporates completely leaving your engine to overheat. Coolant also helps in the protection of inner car parts.

Q: What happens if you put water in the coolant?

You should avoid mixing coolant with ordinary tap water. This water usually has minerals that form deposits in parts of the cooling system or the radiator. Distilled water can be added into the engine but only temporarily. Typically, using water as a coolant is not bad for only a short time or in case of an emergency. However, water lacks corrosion or antifreeze inhibiting properties of an ideal coolant mix. Therefore, water should never be left to stay in the engine for long, more so if you live in the colder areas. If water froze inside the cooling system, the engine would fail.

Q: How long does coolant last in a car?

Engine coolant is made up of a mixture of water and antifreeze. The two are mixed in a 50-50 solution. While the time a coolant should last vary, it is estimated to be about 40,000 to 50,000 miles. This is about 3-5 years after which it should be flushed and changed. However, if you find that you have to refill the coolant constantly, you might want to check for leakages in the system. Also, most service shops advise that you ought to change a coolant more often than it is recommended in a maintenance schedule.

Q: What is the ratio of coolant to water?

The recommended mixing ratio of water to antifreeze is usually either 60:40 or 50:50. This often corresponds to antifreeze protection at the temperature of about -25º C to -40º C. the maximum mixing ratio should be 40:60 while the minimum 70:30. If you increase the amount of antifreeze does not lower the freezing point further. The most beneficial ratio that is recommended is a 50:50 ratio mix.


In as much a lot of people opt to use water in their radiators rather than the coolant, it is not a good idea. If you do not have access to any coolant and using water is the only option, then do so by all means. However, ensure that you buy a coolant the next available moment.

It thus goes without saying that between coolant vs. water, the coolant I the better option. Keep in mind that without a coolant, all the heat dissipated, which is usually two-thirds of the energy produced, may quickly damage the engine.

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